Simply, the hype is true. You have never seen anything like it before.

In classic Cameron fashion, it is a pastiche of lots of great genre history, becoming something that is other than any one part of the past. Avatar is part Lord of The Rings, part West Side Story, part Matrix, part The New World, part Ferngully, part Transformers, part 300, part Aliens, part Star Wars, part Jurassic Park, and on and on. But the thing is, he took most of what he stole – in the best sense of the word – to the next level.

As with Titanic, there is an energy rollercoaster in this 2 hour, 43 minute movie. But Cameron is who he is because he is the ultimate master of the third act. Whatever you have experienced up until then, the third act of Avatar will grab you by the heart and balls, yank hard, and not let go until you are dismissed… AVATAR… Written and Directed by James Cameron.

The movie is a notable advance for performance capture, which is how the Na’vi were created. As was done with Gollum in “The Lord of the Rings” and King Kong in “King Kong”, the Na’vi were made with cameras and sensors recording the movements of the actors and transposing them onto CGI creatures.

Seldom has this been done in a way that captured the most important thing — the eyes — but Cameron employed a new technology (a camera rigged like a helmet on the actors) to capture their faces up close. The green, flickering eyes of the Na’vi are a big step forward, but there’s still an unmistakable emptiness to a movie so filled with digital creations.

Ultimately, the technology of “Avatar” isn’t the problem — moviemaking, itself, is an exercise in technology. But one need look no further than Wes Anderson’s “Fantastic Mr. Fox” to see how technique — whether it be antique stop-motion animation or state-of-the-art 3-D performance capture — can find soulfulness at 24 frames per second.

James Cameron’s 3-D “Avatar” has all the smack of a Film Not To Miss — a movie whose effects are clearly revolutionary, a spectacle that millions will find adventure in. But it nevertheless feels unsatisfying and somehow lacks the pulse of a truly alive film.

Avatar premiered in the UK today. Even though London critics had to sign away their firstborns promising not to review the film until Monday, their drooling reactions are starting to dribble onto the Internet especially via Twitter. I can’t find anyone who seriously says Avatar stinks up the joint. Instead, many are quite effusive in their praise and think it’s kickass spectacular. Generally, the critical reaction is far above average, which bodes well for the film’s word of mouth. Then again, the British may not be familiar with Smurfs.

Avatar is a joyous celebration of story craft and the visual possibilities of cinema.

James Cameron had set his sights on taking the technology of film where no one had gone before. And he delivers. Avatar is stunning. Cameron and Peter Jackson’s Weta Digital (led by VFX master Joe Letteri) have changed the way movies are made.

Disarmingly sincere with its ecological message of being one with nature, Avatar is in tune with Rudyard Kipling’s The Jungle Book, Edgar Rice Burroughs’ Tarzan, Kevin Costner’s Dances with Wolves, Ed Zwick’s The Last Samurai and Terrence Malick’s The New World, in which a stranger/outsider falls in love with an alien culture.

But the storytelling can be lunky, the dialogue at moments, risible: “We’re flying into the flux vortex” and so on. And there are silly bits in the film’s too-long last third, when the battle engages and Sully rises up as the most powerful warrior the Na’vi have ever seen. But hey, these are quibbles. Any self-respecting cinephile will have to see this film, not just once, but over and over again.

Avatar: We shouldn’t really be telling you this – but it’s good
It has been one of the most hyped movies of the decade: the return of James Cameron with a $230m-plus 3D inter-species action movie that will, some observers say, decide the future of the industry.

There have been a lot of rumours. Rumours that the budget was double the stated amount, more like $500m; that the 3D effects were making people nauseous; that the film, two hours and 40 minutes long, was a complete car crash.

The Guardian can reveal that the last two are untrue. The film does not make you feel sick and it is not a disaster. All journalists watching the movie in Fox’s Soho headquarters had to sign a form agreeing not to publish a review or even express a professional opinion online or in print before Monday. So by saying Avatar was really much, much better than expected, that it looked amazing and that the story was gripping – if cheesy in many places – the Guardian is in technical breach of the agreement. It is not a breach, however, to report that other journalists leaving the screening were also positive: the terrible film that some had been anticipating had not materialised. It was good.

There is, though, a certain amount of suspension of disbelief needed when watching Avatar. Cynics might sneer at the plot. The film, set in 2154, revolves around a paraplegic marine assigned to a planet where brutish humans are forcing the natives from their homes to mine a precious mineral, unobtanium, which is the only thing that will keep Earth going.

Bottom Line: A titanic entertainment, movie magic is back!
A dozen years later, James Cameron has proven his point: He is king of the world.

As commander-in-chief of an army of visual-effects technicians, creature designers, motion-capture mavens, stunt performers, dancers, actors and music and sound magicians, he brings science-fiction movies into the 21st century with the jaw-dropping wonder that is “Avatar.” And he did it almost from scratch.